1. Field of the Invention
The present invention relates to a device for processing a microphone signal of a karaoke apparatus, and more particularly to a device in which effects in the case where both an effect and an echo are added to a microphone signal can be rationalized.
The present application is based on Japanese Patent Application No. Hei. 10-286084, which is incorporated herein by reference.
2. Description of the Related Art
A recent karaoke apparatus has a function of adding various effects and echoes to a microphone signal (vocal sound). For example, the following kinds of effects are used.
(a) Harmonizing Function
The pitch of the microphone signal (main melody) is changed on the basis of melody data of each chorus part previously added to music piece data, to produce a song signal of another chorus part. The produced song signal is reproduced by being mixed with the original microphone signal, thereby enabling even a single singer to attain a chorus effect. In some cases, the number of parts to be added can be arbitrarily selected in the range of 1 to about 4.
(b) Doubling Function
The microphone signal is appropriately corrected to produce a signal of the same interval. The produced signal is reproduced by being mixed with the original microphone signal, thereby providing the singing voice with power.
(c) Voice Changing Function
The pitch of the microphone signal is converted to produce a signal of a voice of the opposite sex. The produced signal is also reproduced in place of the original microphone signal. As a result, the voice of a male is converted into that of a female or the voice of a female is converted into that of a male.
(d) Virtual Duet Function
In a duet piece consisting of a male voice part, a female voice part, and a mixed voice part, for the part which is identical with the part of the singer, the microphone signal is reproduced as it is. Meanwhile, for the part of the opposite sex, the pitch of the microphone signal is converted into that of a voice of the opposite sex. Also, for the mixed voice part, a signal which is obtained by converting the microphone signal into a voice of the opposite sex is reproduced while simultaneously reproducing the microphone signal as it is. A single singer is thereby enabled to realize a mixed duet.
(e) Assist Function
The main melody (guide melody) which was previously added to the music piece data is compared with the microphone signal, and the deviation of the interval of the microphone signal is corrected by pitch conversion so that the corrected microphone signal is reproduced in place of the original microphone signal, thereby enabling the song to be heard very well.
FIG. 2 shows the configuration of a portion of a karaoke apparatus which is used for adding an effect and an echo. In this figure, only a portion of one of the right and left channels is shown.
In the karaoke apparatus, music piece data reproduced from a recording medium are supplied to an accompaniment sound generating circuit 10, and a musical sound signal of accompaniment sound is generated. A signal of singing sound of the singer which is collected by a vocal microphone (a microphone signal) is branched in two directions, and the branched signals are supplied in parallel to a dry muting circuit 12 and an effect signal generating circuit 14. The dry muting circuit 12 enables or disables the microphone signal to pass through the dry muting circuit. When the dry mute is off, the pass is enabled; when the dry mute is on, the pass is disabled. The effect signal generating circuit 14 generates an effect signal for the microphone signal, and is configured by, for example, connecting in parallel four routes each having a DSP (Digital Signal Processor). An output signal of the dry muting circuit 12, and that of the effect signal generating circuit 14 are mixed with each other by a mixing circuit 16. An output signal of the mixing circuit 16 is supplied to an echo signal generating circuit 20 to generate an echo signal.
A mixing circuit 18 mixes the generated echo signal with the signal of the mixing circuit 16 to which the echo is not added, and outputs the mixed signal as a final signal of the singing sound. A mixing circuit 22 mixes the signal of the singing sound with the signal of the accompaniment sound. An output signal of the mixing circuit 22 is amplified by an amplifier 24 and the amplified signal is reproduced by a loudspeaker 26.
In response to an operation of the user, an effect operating section 28 conducts various instruction operations such as the on/off state of each effect, selection of the kind of effect mode, and adjustment of the additional amount of the effect. For example, the kinds of effects include the harmonizing function, the doubling function, the voice changing function, the virtual duet function, and the assist function which are described above. The additional amount of the effect corresponds, for example, to the volume of an effect signal in the harmonizing function, the doubling function, or the like, the number of parts to be added in the harmonizing function, the number of superimposed corrected sounds in the doubling function, etc. An effect control information extracting circuit 30 extracts effect control information which is contained, for example, in music piece data as note information of a MIDI signal. For example, the effect control information includes main melody (guide melody) information used in the assist function, melody information of a part to be added in the harmonizing function, melody information of each part used in the virtual duet function, etc. An effect controlling circuit 32 controls the effect signal generating circuit 14 in accordance with various instructions in the effect operating section 28 and the effect control information, to generate an effect signal corresponding to the instructions and the effect control information.
In response to an operation of the user, an echo operating section 34 conducts various instruction operations such as the on/off state of each echo, selection of the kind of echo mode, and adjustment of the echo level. An echo controlling circuit 36 controls the echo signal generating circuit 20 in accordance with various instructions in the echo operating section 34, to generate an echo signal corresponding to the instructions.
In the circuit of FIG. 2, in accordance with the kind of effect, the dry muting circuit 12 and the effect signal generating circuit 14 are controlled in the following manner in accordance with the kind of effect.
(a) Harmonizing Function
The dry muting circuit 12 is turned off to enable the original microphone signal to pass through the circuit. The effect signal generating circuit 14 converts the pitch of the original microphone signal using the four routes, to generate signals of the parts to be added, and outputs the part which is designated by the operation of the user. The mixing circuit 16 mixes the original microphone signal (the main melody) with the signal of the part to be added, and outputs the mixed signal.
(b) Doubling Function
The dry muting circuit 12 is turned off to enable the original microphone signal to pass through the circuit. The effect signal generating circuit 14 generates a signal which is obtained by correcting the original microphone signal by, for example, one of the routes, and outputs the corrected signal. The mixing circuit 16 mixes the original signal with the corrected signal and outputs the mixed signal.
(c) Voice Changing Function
The dry muting circuit 12 is turned on to disable the original microphone signal from passing through the circuit. The effect signal generating circuit 14 generates a signal which is obtained by converting the pitch of the original microphone signal using one of the routes to that of a voice corresponding to instructions given by the user (e.g., conversion from a male voice to a female voice or from a female voice to a male voice), and outputs the pitch-converted signal. The mixing circuit 16 outputs only the pitch-converted signal.
(d) Virtual Duet Function
The dry muting circuit 12 is turned on to disable the original microphone signal from passing through the circuit. The effect signal generating circuit 14 generates a signal which is obtained by converting the pitch of the original microphone signal to the voice of the opposite sex using one of the routes in accordance with instructions relating to the sex (i.e., a male singing or a female singing) and given by the user. The circuit 14 then enables the original microphone signal to be passed through another route without undergoing conversion, and, with the progress of accompaniment sound, outputs the signal of the corresponding part in accordance with the information indicative of a male voice part, a female voice part, or a mixed voice part and given in the effect control information. The mixing circuit 16 outputs only the signals output from the effect signal generating circuit 14.
(e) Assist Function
The dry muting circuit 12 is turned on to disable the original microphone signal from passing through the circuit. The effect signal generating circuit 14 generates a signal which is obtained by correcting the original microphone signal in accordance with the guide melody by one of the routes, and outputs the corrected signal. The mixing circuit 16 outputs only the corrected signal.
In the circuit of FIG. 2, the generation of the echo signal by the echo signal generating circuit 20 is conducted in accordance with only the instructions given by the echo operating section 34, and irrespective of the kind of effect. In this case, in an effect mode such as the harmonizing function or the doubling function in which the original signal and an effect signal are added together and a result of the addition is output, even this effect is sufficient for attaining a reverberation effect. When an echo is further added, however, it is often that the effect (reverberation and the like) is excessively increased and listening or singing is hardly conducted.